GEOGRAPHY
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dry months from November to March yield only nine inches as compared with 76 inches spread over the other seven months. There is also considerable variation in rainfall over different parts of the Colony. The wettest areas are the mountain regions, particularly around Tai Mo Shan and on Lantau Island. Least rainfall occurs on the smaller islands, which usually receive little more than half the rainfall of the wettest areas.
The mean daily temperature ranges from about 58°F in February to over 82°F in July and the average for the year is 72°F. During the hottest month, July, the mean maximum temper- ature is 86.9°F, but the summer temperature often exceeds 90°F. February is the coldest month with a mean minimum temperature of 55.6°F, but the temperature can be expected to fall to 45°F in most years. Temperatures above 95°F or below 40°F are rarely recorded at the Observatory although greater extremes occur in the New Territories. Ice occasionally forms on high ground. Afternoon temperatures are usually 8°F to 9°F higher than during the coldest part of the night. The mean relative humidity exceeds 80 per cent from mid-February until early September. November is the least humid month with 69 per cent relative humidity, but the lowest reading of 10 per cent was recorded in January. The average daily duration of bright sunshine ranges from three hours in March to over seven hours in mid-July and late October.
Gales caused by tropical cyclones may be expected in any of the months from May to November, but they are most likely from July to September. The passage of these cyclones several times a year at varying distances from Hong Kong brings spells of bad weather with strong winds and heavy rain. Gales are experienced once a year on average, and less frequently the centre of a mature typhoon passes sufficiently close to the Colony to produce winds of hurricane force when damage and loss of life may occur. The last occasion when such winds were experienced was in September 1962 when the centre of typhoon Wanda passed over the southern part of the Colony.